Originally Posted by
C.F.I. Care
Anyone ever flip on their battery master switch and not get the low rotor rpm tone? Or get just the gong instead? Or no sound at all?
Some more detail:
Ship is a P1. A previous warning unit worked great for about a year, then it started to act up. Sometimes when we turned on the master battery switch it worked correctly, you’d get the low rotor rpm tone, hit reset on the cyclic, then get the gong. But intermittently, we’d get no low rotor rpm tone, just straight to the gong, and sometimes neither tone, just silence.
We replaced that one and it worked fine for another year. Then we figured out the warning unit we put in wasn’t calibrated for the 95% low rotor rpm threshold for the P1, but instead for 97%. So we got a brand new unit from Airbus (complete with a check engine light…), calibrated for 95% and stuck it in. Now we’re having the same intermittent issue with the tones not coming on when you flip on the battery master.
Could this be a voltage thing? Could low battery voltage cause the warning unit not to make the tones? Could this be a compatibility thing between the new unit and the old aircraft?
Thanks!
One of our cabs has got the same problem, it's also a P1 of '99 vintage but the warning still works when you toggle the test switch and when you explore the limits.